Flame-retardant polyester-based fiber for artificial hair

ABSTRACT

A polyester fiber having outstanding flame resistance, curl-setting property, melt-drip-proof property, transparency, devitrification resistance, and controlled gloss of fiber, while maintaining physical properties of usual polyester fibers, such as heat-resistance and tensile elongation and strength is provided. A flame retardant polyester fiber for artificial hair that can solve the problem may be obtained by melt-spinning a composition obtained by melt-kneading 2 to 20 parts by weight of organic cyclic phosphorus compounds and/or phosphoric ester amido compounds (B) into 100 parts by weight of a polyester (A) comprising one or more kinds of polyalkylene terephthalates and copolymerized polyesters having a polyalkylene terephthalate as a principal component, and a composition obtained by blending organic fine particles (C) and/or inorganic fine particles (D) into the above-mentioned composition.

FIELD OF THE INVENTION

The present invention relates to a fiber for flame retardant polyesterartificial hair made of a composition obtained by melt-kneading aspecific phosphorus containing flame retardant agent into polyesters. Inmore detail, the present invention relates to a fiber for artificialhair having outstanding curl-setting and holding property,melt-drip-proof property, transparency, and devitrification resistance,while maintaining physical properties of the fiber, such as flameresistance, heat resistance, and tensile elongation and strength.

BACKGROUND ART

Since fibers made of polyethylene terephthalate, or polyesterscomprising polyethylene terephthalate as a principal component have ahigh melting point and high modulus of elasticity, and may demonstrateoutstanding heat resistance and chemical resistance, they have widelybeen used for curtains, mattings, clothes, blankets, sheets,tablecloths, fabric upholstery, wall covering materials, artificialhair, and automobile interior finishing materials, outdoorreinforcement, safety nets, etc.

Human hair, artificial hair (modacrylic fiber, polyvinyl chloridefiber), etc. have conventionally been used in hair products, such aswigs, hair wigs, extensions, hair bands, and doll hair. However, humanhair is being difficult in availability and therefore importance ofartificial hair is now increasing.

Although many modacrylic fibers have been used as artificial hairmaterials by utilizing flame resistance, it is inadequate in respect ofheat resistance. In recent years, artificial hair is proposed that usesfibers having polyesters represented by polyethylene terephthalate withexcellent heat resistance as a principal component.

However, since fibers obtained from polyesters represented bypolyethylene terephthalate is flammable materials, it has inadequateflame resistance.

Conventionally, various attempts to improve flame resistance ofpolyester fibers have been performed, and there are known, for example,a method to use fibers made of polyesters copolymerized with flameretardant monomers including phosphorus, and a method to add flameretardant agents in polyester fibers.

As methods of copolymerization with the former flame retardant monomers,for example, there have been proposed a method (Japanese PatentPublication No. 55-41610 official report) of copolymerization withphosphorus compounds, giving satisfactory thermal stability, havingphosphorus atom as a ring member; a method of copolymerization withcarboxy phosphinic acids (Japanese Patent Publication No. 53-13479official report); and a method of blending or copolymerization withphosphorus compounds to polyesters comprising polyarylate (JapanesePatent Laid-Open No. 11-124732 official report).

As examples of application to artificial hair of the flame resistancetechnique, for example, proposed is a polyester fiber obtained bycopolymerization of a phosphorus compound. (Japanese Patent Laid-OpenNo. 3-27105 official report, and Japanese Patent Laid-Open No. 5-339805official report).

However, since artificial hair needs high flame resistance, use of thesecopolymerized polyester fibers need a great amount of copolymerization,other problems may occur that the copolymerization greatly reduces heatresistance of the polyester, makes melt spinning difficult, and also mayinduce melting and dripping although not causing firing and burning, inapproach to a flame. In blending of the phosphorus based flame retardantagent, there occur such a problem that an artificial hair comprising anobtained polyester fiber easily gives a problem of visual appearance ofthe fiber called devitrification, under conditions of exposure to heator high humidity, in addition to increase in sticky touch resulting froma large quantity of additions needed for expression of flame resistance.

Thus, artificial hairs having excellent curl-setting and retentiveproperty is not yet obtained, while maintaining fiber physicalproperties, such as flame resistance, heat resistance, strength,elongation, etc. of conventional polyester fibers.

SUMMARY OF THE INVENTION

As a result of repeated investigation wholeheartedly carried out by thepresent inventors in order to solve the above-mentioned problems, it wasfound out that there may be obtained flame retardant polyester fibersfor artificial hair having outstanding flame resistance, curl-settingand retentive property, melt-drip-proof property, transparency, anddevitrification resistance, while maintaining physical properties offibers found in usual polyester fibers, such as heat resistance andtensile elongation and strength, by melt-spinning of a compositionobtained by melt kneading of organic cyclic phosphorus compounds and/orphosphoric ester amido compounds into polyesters. The organic cyclicphosphorus compounds and/or the phosphoric ester amido compounds foundout in the present invention can exhibit sufficient flame resistance andcan maintain physical properties of the fiber even with smaller additionas compared with additive type phosphorus based flame retardant agentsconventionally used. Furthermore, since a phosphorus based flameretardant agent unit is not introduced into a polymer principal chain ascompared with reactive type phosphorus based flame retardant agents, thecompounds can maintain heat resistance and melt-drip-proof property ofthe fiber. In addition, it was also found out that blending of organicfine particles and/or inorganic fine particles into the compositionenables control of gloss of the fiber, without causing deterioration ofphysical properties of the fiber, thus leading to completion of thepresent invention.

That is, the present invention relates to a flame retardant polyesterfiber for artificial hair made of a composition obtained by meltkneading: 100 parts by weight of a polyester (A) comprising one or morekinds selected from polyalkylene terephthalates and copolymerizedpolyesters having a polyalkylene terephthalate as a principal componentand 2 to 20 parts by weight of an organic cyclic phosphorus compoundand/or a phosphoric ester amido compound (B), wherein the component (A)preferably is at least one kind of polymers selected from a groupconsisting of polyethylene terephthalate, polypropylene terephthalate,and poly butylene terephthalate, the component (B) is an organic cyclicphosphorus compound and/or a phosphoric ester amido compound representedby general formulas (1) to (9):

(where, R¹ represents a hydrogen atom, or a linear alkyl group, or analkyl group having a branch, and each of the R¹ may be identical ordifferent from each other, and R² represents a hydrogen atom, a linearalkyl group, or an alkyl group having a branch, a linear hydroxy alkylgroup, or a hydroxy alkyl group having a branch, a cycloalkyl group, asubstituted or non-substituted aryl group, or a substituted ornon-substituted aralkyl group);

(where, R¹ represents a hydrogen atom, a linear alkyl group, or an alkylgroup having a branch, and each of the R¹ may be identical or differentfrom each other, R³ represents a divalent linear alkylene group, or adivalent alkylene group having branch, a linear hydroxy alkyl group, ora hydroxy alkyl group having a branch, a cycloalkylene group, analkylene group having ether oxygen in a principal chain thereof, asubstituted or non-substituted aryl group, a substituted ornon-substituted aralkyl group, an α,α′-xylylene group, asubstituted-α,α′-xylylene group, an α,α′-meta-xylylene group, or asubstituted-α,α′-xylylene group);

(where, R¹ represents a hydrogen atom, a linear alkyl group, or an alkylgroup having a branch, and each of the R¹ may be identical or differentfrom each other, R⁴ represents a hydrogen atom, a linear alkyl group, oran alkyl group having a branch, a cycloalkyl group, a substituted ornon-substituted aryl group, or a substituted or non-substituted aralkylgroup);

(where, R¹ represents a hydrogen atom, a linear alkyl group, or an alkylgroup having a branch, and each of the R¹ may be identical or differentfrom each other, and R⁵ represents a divalent linear alkylene group or adivalent alkylene group having branch, a cycloalkylene group, analkylene group having ether oxygen in a principal chain thereof, asubstituted or non-substituted aryl group, a substituted ornon-substituted aralkyl group, an α,α′-xylylene group, asubstituted-α,α′-xylylene group, an α,α′-meta-xylylene group, or asubstituted-α,α′-xylylene group);

(where, R¹ represents a hydrogen atom, a linear alkyl group, or an alkylgroup having a branch, and each of the R¹ may be identical or differentfrom each other, R⁶ represents a divalent linear alkylene group or adivalent alkylene group having branch, a cycloalkylene group, R⁷represents a hydrogen atom, a linear alkyl group, or an alkyl grouphaving a branch, each of the groups may be identical or different fromeach other, n represents 1 to 6);

(where, R¹ represents a hydrogen atom, a linear alkyl group, or an alkylgroup having a branch, and each of the R¹ may be identical or differentfrom each other, R⁸ and R⁹ represent a hydrogen atom, a linear alkylgroup, or an alkyl group having a branch, or a cycloalkyl group, Yrepresents a hydrogen atom, a linear alkyl group, or an alkyl grouphaving a branch, a cycloalkyl group, a substituted or non-substitutedaryl group, or a substituted or non-substituted aralkyl group, each ofthem may be identical or different from each other, and m represents 1to 3);

(where, R¹ represents a hydrogen atom, a linear alkyl group, or an alkylgroup having a branch, and each of the R¹ may be identical or differentfrom each other, R¹⁰ represents a divalent linear alkylene group or adivalent alkylene group having branch, a linear hydroxy alkyl group, ora hydroxy alkyl group having a branch, a cycloalkylene group, analkylene group having ether oxygen in a principal chain thereof, asubstituted or non-substituted aryl group, or a substituted ornon-substituted aralkyl group, X represents oxygen atom or sulfur atom,and 1 represents 0 or 1);

(where, R¹¹ represents a hydrogen atom, a linear alkyl group, or analkyl group having a branch, and each of the R¹¹ may be identical ordifferent from each other, R¹² and R¹³ represent a hydrogen atom, alinear alkyl group, or an alkyl group having a branch, a linear hydroxyalkyl group, or a hydroxy alkyl group having a branch, a cycloalkylgroup, a substituted or non-substituted aryl group, or a substituted ornon-substituted aralkyl group, and q represents 1 or 2);

(where, R¹¹ represents a hydrogen atom, a linear alkyl group, or analkyl group having a branch, and each of the R¹¹ may be identical ordifferent from each other, R¹⁴ and R¹⁵ represent a divalent linearalkylene group or a divalent alkylene group having branch, a linearhydroxy alkyl group, or a hydroxy alkyl group having a branch, acycloalkylene group, an alkylene group having ether oxygen in aprincipal chain thereof, a substituted or non-substituted aryl group, ora substituted or non-substituted aralkyl group).

The present invention further relates to the flame retardant polyesterfiber for artificial hair, fine projections being formed on a surface ofthe fiber by blending organic fine particles (C) and/or inorganic fineparticles (D) to a composition consisting of component (A) and component(B), wherein the component (C) is at least one kind of material selectedfrom a group consisting of polyarylates, polyamides, fluororesins,silicone resins, cross-linked acrylic resins, and cross-linkedpolystyrenes, and the component (D) is at least one kind of materialselected from a group consisting of calcium carbonate, silicon oxide,titanium oxides, aluminum oxide, zinc oxide, talc, kaolin,montmorillonite, bentonite, and mica. In addition, the flame retardantpolyester fiber for artificial hair preferably is of a form ofnon-crimped fiber, is spun-dyed, and has a single fiber size of 5 to 100dtex.

BEST MODE FOR CARRYING-OUT OF THE INVENTION

A flame retardant polyester fiber for artificial hair of the presentinvention is a melt-spun fiber of a composition obtained bymelt-kneading of 100 parts by weight of a polyester (A) comprising oneor more kinds selected from polyalkylene terephthalates andcopolymerized polyesters having a polyalkylene terephthalate as aprincipal component, and 2 to 20 parts by weight of an organic cyclicphosphorus compound and/or a phosphoric ester amido compound (B).

As polyalkylene terephthalates or copolymerized polyesters havingpolyalkylene terephthalate as a principal component included in apolyester (A) used for the present invention, for example, there may bementioned: polyalkylene terephthalates such as polyethyleneterephthalate, polypropylene terephthalate, polybutylene terephthalate,and/or copolymerized polyesters having polyalkylene terephthalate as aprincipal component, including a small amount of copolymerizablecomponents.

The principal component represents a component having a content of notless than 80 mol %.

The copolymerizable components include, for example: polyvalentcarboxylic acids, such as isophthalic acid, ortho-phthalic acid,naphthalene dicarboxylic acid, para-phenylene dicarboxylic acid,trimellitic acid, pyromellitic acid, succinic acid, glutaric acid,adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioicacid, and derivatives of the above-mentioned acids; dicarboxylic acidscomprising sulfonate, such as 5-sodium sulfo isophthalate, 5-sodiumsulfoisophthalate dihydroxy ethyl, etc., and derivatives of theabove-mentioned acids; and 1,2-propanediol, 1,3-propanediol,1,4-butanediol, 1,6-hexane diol, neopentylglycol, 1,4-cyclohexanedimethanol, diethylene glycol, polyethylene glycol, tri-methylolpropane, penta erythritol, 4-hydroxybenzoic acid, ε-caprolactone, etc.

It is preferable, in view of stability and simpler operation, that thecopolymerized polyester is usually manufactured by adding a small amountof copolymerizable components into a polymer obtained from terephthalicacid and/or a derivative thereof (for example, methyl terephthalate) asa principal component, and an alkylene glycol, and by reacting themtogether. Otherwise the copolymerized polyester may also be manufacturedby adding a small amount of a monomer or oligomer component as acopolymerizable component into a mixture of terephthalic acid and/or aderivative thereof (for example, methyl terephthalate) as a principalcomponent, and alkylene glycol, and by polymerizing the resultingmixture.

In the copolymerized polyester, the above-mentioned copolymerizablecomponents may just be polycondensed with a principal chain and/or aside-chain of the polyalkylene terephthalate as a principal component,and methods of copolymerization is not especially limited.

Examples of the copolymerized polyester having the polyalkyleneterephthalate as a principal component include, for example, polyestershaving polyethylene terephthalate as a principal component and obtainedby copolymerization with ethylene glycol ether of bisphenol A, with1,4-cyclohexane dimethanol, or with 5-sodium sulfoisophthalate dihydroxyethyl etc.

The polyalkylene terephthalate and the copolymerized polyester may beused independently, and they may also be used in combination. In theabove-mentioned polyesters, there may be preferably used polyethyleneterephthalate, polypropylene terephthalate, polybutylene terephthalate,copolymerized polyesters (polyester having polyethylene terephthalate asa principal component and being obtained by copolymerization withethylene glycol ether of bisphenol A, with 1,4-cyclohexane dimethanol,or 5-sodium sulfo isophthalate dihydroxy ethyl). These may alsopreferably be used in combination.

An intrinsic viscosity of the component (A) is preferably 0.5 to 1.4,and more preferably it is 0.6 to 1.2. An intrinsic viscosity less than0.5 tends to reduce mechanical strength of fibers obtained. Otherwise anintrinsic viscosity exceeding 1.4 tends to cause increase of meltviscosity accompanied by increase of a molecular weight of the fiber,and also results in difficulty in melt-spinning, leading to unevennesssize of a fiber.

The organic cyclic phosphorus compound and/or phosphoric ester amidocompound (B) used for the present invention has a structure representedby general formulas (1) to (9), and in detail examples of the compoundinclude: compounds represented by general formula (1),

compounds represented by general formula (2),

compounds represented by general formula (3),

compounds represented by general formula (4),

compounds represented by general formula (5),

compounds represented by general formula (6),

compounds represented by general formula (7),

compounds represented by general formula (8),diphenyl(cyclohexylamido)phosphate, diphenyl(diethylamido)phosphate,diphenyl(morphorido)phosphate, diphenyl(octylamido)phosphate,diphenyl(benzylamido)phosphate, diphenyl(allylamido)phosphate,diphenyl(anilido)phosphate, (dimorphorido)phenyl phosphate etc.; and,compounds represented by general formula (9),

etc.

An amount of the component (B) to be used is preferably 2 to 20 parts byweight to the component (A) 100 parts by weight, more preferably 3 to 18parts by weight, and still more preferably 4 to 16 parts by weight. Anamount to be used smaller than 2 parts by weight deterioratesfire-resistant effect, and an amount exceeding 20 parts by weightimpairs mechanical property, heat resistance, melt-drip-proof property,and devitrification resistance.

In the flame retardant polyester fiber for artificial hair of thepresent invention, organic fine particles (C) and/or inorganic fineparticles (D) may be blended to form fine projections on a surface ofthe fiber, allowing adjustment of gloss and luster of the surface of thefiber. Combined use of the component (C) and/or (D) with the organiccyclic phosphorus compounds and/or phosphoric ester amido compounds (B)used in the present invention enables the obtained fiber to demonstratemore natural gloss and more natural luster as compared with cases usingother phosphorus based flame retardant agents.

As the component (C), organic resin components without compatibility orhaving partial compatibility with respect to the component (A) and/orcomponent (B) as a principal component may be used, and there may beused, for example, polyarylates, polyamides, fluororesins, siliconeresins, cross linked acrylic resins, cross linked polystyrenes, etc.These may be used independently and two or more kinds may be used incombination.

As a component (D), components having a refractive index close to arefractive index of the component (A) and/or (B) are preferable, from aviewpoint of effect on transparency, and color vividness of fiber, andfor example, calcium carbonate, silicon oxide, titanium oxide, aluminumoxide, zinc oxide, talc, kaolin, montmorillonite, bentonite, mica, etc.may be mentioned.

A flame retardant polyester composition used for the present inventionmay be manufactured, for example, in such a manner that the component(A) and the component (B), and, if needed, the component (C) or thecomponent (D) are dry-blended beforehand, and an obtained blendedmaterial is subsequently melt-kneaded using various common mixingdevices. Examples of the mixing devices include, for example, a singlescrew extruder, a double screw extruder, rolls, a Banbury mixer, akneader, etc. From a viewpoint of adjustment of a degree of kneading,and simpler operation, a double screw extruder is preferable among them.

The flame retardant polyester fiber for artificial hair of the presentinvention may be manufactured by melt-spinning of the flame retardantpolyester composition, using usual melt-spinning methods.

That is, an extruded yarn may be obtained in such a manner thatmelt-spinning is performed under conditions of temperatures of anextruder, a gear pump, spinneret, etc. as 270 to 310 degrees C., andsubsequently the obtained extruded yarn is cooled at temperatures notmore than a glass transition temperature, after passing the extrudedyarn through a heated tube, and subsequently is taken up at a take-upspeed of 50 to 5000 m/minute. In addition, the extruded yarn may also becooled in a water tank for cooling to control of a size of a fiber. Atemperature and a length of heated tube, a temperature and an amount ofcooling gas, a temperature of cooling water tank, cooling time, and ataking up velocity may be appropriately adjusted based on an extrudedamount, and a number of holes of a spinneret.

The obtained un-drawn yarn is stretched by heating. Stretching may beperformed by any methods of a two-step method of stretching beingperformed after taking up of the un-drawn yarn, and a direct spinningand stretching method of stretching being performed without taking up.Hot stretching is performed by one-stage stretching method or two ormore stages of multistage stretching method. As heating means in hotstretching, heating rollers, heat plates, steam jet devices, warm waterbath, etc. may be used, and they may also be used in combination.

Various additives, such as flame retardant agents other than thecomponent (B), heat-resistant agents, light stabilizers, fluorescenceagents, antioxidants, antistatic agents, pigments, plasticizers, andlubricants, may be added into the flame retardant polyester fiber forartificial hair of the present invention, if necessary. Spun dyed fibersmay be obtained by adding pigments.

Thus obtained flame retardant polyester fiber for artificial hair of thepresent invention is non-crimped fiber, and the size of the fiber isusually 30 to 80 dtex for artificial hair, and preferably 35 to 75 dtex.In addition, as a fiber for artificial hair, the fiber preferably hasheat-resistance for a cosmetics heat instrument (hair iron) used attemperatures of 160 to 200 degrees C., anti-flammability, andself-extinguishing property.

When the flame retardant polyester fiber of the present invention isspun dyed, it can be used untreated, and when the fiber is notspun-dyed, the fiber may be dyed on same conditions for usual flameretardant polyester fibers.

As pigments, dyestuffs, auxiliary agents, etc. to be used for dyeing,materials having excellent weather resistance and flame resistance arepreferably used.

The flame retardant polyester fiber for artificial hair of the presentinvention has outstanding curl setting properties by a cosmetics heatinstrument (hair iron), and also has excellent curl retentiveproperties. In addition, unevenness of the surface of the fiber may givemoderate matting effect, and thus the fiber may be used as artificialhair. Furthermore, use of oils, such as fiber surface treating agentsand softening agents, gives improved feeling and touch to the fiber, andthereby the fiber may be more close to human hair.

In addition, the flame retardant polyester fiber for artificial hair ofthe present invention may be used together with other artificial hairmaterials, such as modacrylic fibers, polyvinyl chloride fibers, andnylon fibers, and also may be used in combination with human hair.

Since human hairs used for hair products, such as wigs, hair wigs, andfalse hairs is usually given removing treatment for cuticles,decolorized and dyed, and silicone based fiber surface treating agentsand softening agents are used in order to secure feeling and combingproperty, these human hairs are flammable unlike untreated human hairs.Blending of the flame retardant polyester fiber for artificial hair ofthe present invention and human hair by not more than 60% of human haircontent may exhibit excellent flame resistance.

EXAMPLE

The present invention will, hereinafter, be described in still moredetails, referring to Examples, but the present invention is not limitedto these Examples.

Measurement of physical property values was performed according tofollowing methods.

(Strength and Elongation)

A filament was measured for a tensile elongation and strength usingINTESCO Model 201 type made by INTESCO, Ltd. One filament with a lengthof 40 mm was sampled, both ends of the filament was sandwiched by 10 mmwith cardboard (thin paper) with which double-stick tape havingadhesives thereon was attached, and after air dried overnight, and asample with a length of 20 mm was prepared. The obtained sample wasclamped with a testing machine, examination was performed underconditions of temperature of 24 degrees C., not more than 80% ofhumidity, load 1/30 gf×size of a fiber (denier), and a speed oftesting/minute of 20 mm, and tensile elongation and strength wasdetermined. Examination was repeated 10 times on same conditions, andobtained average value was defined as a tensile elongation and strengthof the filament.

(Flame Resistance)

A filament having a size of a fiber of approximately 50 dtex is cut by alength of 150 mm. The filament 0.7 g was bundled, clamped at one end bya jaw, and was hung down perpendicularly in a state fixed to a stand. Aflame having a length of 20 mm was contacted on the fixed filamenthaving 120 mm of effective length for 3 seconds, and the filament wasmade to burn. Flammability evaluation was given as follows: Residualflame time 0 second (not burn) as Very good, less than 3 seconds asGood,

3 seconds to 10 seconds as Fair, and

not less than 10 seconds as Bad.

Evaluation of melt-drip-proof property was given as follows: number ofdrips until extinguished 0 as Very good, not more than 5 as Good,

6 to 10 as Fair, and

not less than 11 as Bad.

(Gloss)

A tow filament with length of 30 cm and gross size of 100,000 dtex wereevaluated under sunlight by visual inspection.

Very good: gloss adjusted to a level similar to human hair

Good: gloss adjusted moderately

Fair: a little excessive or a little insufficient gloss

Bad: excessive gloss, or insufficient gloss

(Transparency)

A tow filament with length of 30 cm and gross size of 100,000 dtex wereevaluated under sunlight by visual inspection.

Good: having depth of color (vividness) and transparence

Fair: a little opacity (haze)

Bad: having opacity and no depth of color.

(Devitrification Resistance)

A tow filament with length of 10 cm and gross size of 100,000 dtex weresubjected to steaming treatment (at 120 degrees C. and 100% of relativehumidity 1 hour), and then was fully dried at room temperature.Variations of gloss and hue before and after steam processing werecompared for evaluation by visual inspection. Larger variations beforeand after steam processing meant worse devitrification resistance.

Very good: gloss and hue have no variation.

Good: no gloss variation and a little variation

Fair: some variations in gloss and hue

Bad: clear variation in gloss and hue

(Curl Setting Property)

Filaments in a weft hair were wound around a pipe of 32 mm φ, and curlset by steam was given under conditions for 120 degree C., 100% ofrelative humidity, and 60 minutes. After aging for 60 minutes at roomtemperature, an end of the curled weft hair was fixed to be hung downfor evaluation of curling state by visual inspection. This was definedas an index of curl retentive property. A state with a smaller lengthand with curl in sufficient form is preferable.

Good: curl in sufficient form

Fair: curl relaxed a little

Bad: curl loosened and form collapsed

(Iron Set Property)

This is an index of easiness of curl-setting and of retentivity of curlshape by a hair iron. Filaments were preheated by being lightlysandwiched and rubbed by a hair iron heated at 180 degrees C. threetimes. Adhesion and combing among the filaments, and frizz and breakageof the filaments were visually evaluated at this time. Next, thepreheated filament was wound around a hair iron and held for 10 seconds,and then the hair iron was withdrawn. Easiness of withdrawing (rod outproperty) at this time and retentivity of curl were evaluated by visualinspection.

Examples 1 to 16

A polyester pellet PESM6100 BLACK for coloring (manufactured byDainichiseika Colour & Chemicals Mfg. Co., Ltd., 30% of carbon blackcontents: polyester content is included in the component (A) aspolyester) 2 parts by weight was added to compositions having ratiosshown in Table 1 comprising: a polyethylene terephthalate dried so as tohave moisture content of not more than 100 ppm, phosphorus containingflame retardant agents, organic fine particles, and inorganic fineparticles, and dry-blended. The obtained mixtures were delivered to atwin screw extruder, and were melt-kneaded at 280 degrees C. to bepelltized. And subsequently the pellets obtained were dried to not morethan 100 ppm of moisture content. Subsequently, molten polymers wereextruded from a spinneret having circle section holes of 0.5 mm ofdiameters of spinneret, using a melt spinning machine at 280 degrees C.The obtained filaments were cooled in a water bath with a watertemperature of 50 degrees C. installed in a position of 30 mm under thespinneret, and taken up at a rate of 100 m/minute to obtain un-drawnyarns. The obtained un-drawn yarns were drawn in a warm water bath at 80degrees C to provide four times drawn yarns. The drawn yarns were takenup using a heat roll heated at 200 degrees C., and at a rate of 100m/minute to be heat-treated. Polyester fibers (multifilament) having asingle fiber fineness of about 50 dtex were obtained. TABLE 1 EXAMPLE 12 3 4 5 6 7 8 9 10 11 12 Polyethylene terephthalate*¹ 100 100 100 100100 100 100 100 100 100 100 100 Phosphorus containing flame 4 8 8 8retardant agent (1)*² Phosphorus containing flame 6 10 retardant agent(2)*³ Phosphorus containing flame 4 8 retardant agent (3)*⁴ Phosphoruscontaining flame 6 retardant agent (4)*⁵ Phosphorus containing flame 10retardant agent (5)*⁶ Phosphorus containing flame 8 retardant agent(6)*⁷ Phosphorus containing flame 6 retardant agent (7)*⁸ Polyarylate*⁹1 0.4 0.8 Talc*¹⁰ 1 0.8 0.8 0.8 0.6 1 0.8 1 0.8 1.0 Silica*¹¹ 1 0.8 0.80.6 1 0.8 1 0.8 1.0 *¹BELLPET EFG-85A, manufactured by Kanebo Gohsen,Ltd. *²

*³

*⁴

*⁵

*⁶

*⁷

*⁸

*⁹U-polymer U-100, manufactured by Unitika, Ltd. *¹⁰PKP-53, manufacturedby Fuji Talc *¹¹IMSIL A-8, manufactured by UNIMIN CORPORATION

The obtained fibers were evaluated for tensile elongation and strength,flame resistance, gloss, transparency, devitrification resistance, coldsetting property, curl holding power, and iron set property. Table 2 andTable 3 show results. TABLE 2 EXAMPLE 1 2 3 4 5 6 7 8 9 10 Size of afiber (dtex) 52 51 50 52 52 50 53 50 52 52 Strength (cN/dtex) 2.9 2.72.7 2.7 2.7 2.6 2.4 2.3 2.3 2.2 Elongation (%) 48 45 45 45 47 46 41 4048 48 Flame Combustibility Good Very Very Very Good Very Good Very GoodVery resistance good good good good good good Melt-drip-proof Good VeryVery Very Very Very Good Good Good Good good good good good good GlossGood Good Good Good Good Good Good Good Good Good Transparency Good GoodGood Good Good Good Good Good Good Good Devitrification resistance GoodGood Good Good Good Good Good Good Good Good Curl setting Good Good GoodGood Good Good Good Good Good Good Iron set Adhesion Good Good Good GoodGood Good Good Good Good Good property Frizz/Breakage Good Good GoodGood Good Good Good Good Good Good (180 Rod out Good Good Good Good GoodGood Good Good fair fair degrees) Setting Good Good Good Good Good GoodGood Good Good Good

TABLE 3 EXAMPLE Comparative Example 11 12 1 2 3 Size of a fiber (dtex)53 50 48 50 49 Strength (cN/dtex) 2.6 2.3 2.0 2.0 2.5 Elongation (%) 4246 63 58 46 Flame Combusti- Very Good Fair Fair Very resistance bilitygood good Melt-drip- Very Good Bad Bad Good proof good Gloss Good GoodFair Fair Bad Transparency Good Good Fair Fair Good Devitrification GoodGood Fair Fair Fair resistanc Curl-setting Good Good Good Good Good Ironset Adhesion Good Good Bad Bad Good property Frizz/ Good Good Fair FairGood (180 Breakage degrees) Rod out Good Good Bad Bad Fair Setting GoodGood Good Good Good

Comparative Example 1

To a polyethylene terephthalate (BELLPET EFG-85A, manufactured by NipponUNIPET, Ltd.) dried by not more than 100 ppm of moisture contents 100parts by weight, 1,3-phenylene bis(dixylenyl phosphate) 10 parts byweight, titanium oxide 1 part by weight, and polyester pellet forcoloring PESM6100 BLACK (manufactured by Dainichiseika Colour &Chemicals Mfg. Co., Ltd., 30% of carbon black content) 2 parts by weightwere added and dry-blended. Molten polymer was extruded using aspinneret having circle section spinneret hole of 0.5 mm of diameters,was cooled in a water bath with water at a temperature of 30 degrees C.installed in a position of 25 cm under the spinneret, and taken up at arate of 100 m/minute to obtain un-drawn yarns. The obtained un-drawnyarns were drawn in a warm water bath at 80 degrees C. to obtain fourtimes drawn yarns. The drawn yarns were taken up using a heat rollheated at 200 degrees C., and at a rate of 100 m/minute to beheat-treated. Polyester fibers (multifilament) having a single fiberfineness of about 49 dtex were obtained.

Comparative Example 2

To a polyethylene terephthalate (BELLPET EFG-85A, manufactured by NipponUNIPET, Ltd.) dried by not more than 100 ppm of moisture contents 100parts by weight, added were 1,3-phenylene-bis(dixylenyl phosphate) 10parts by weight, talc (PKP-53, product made from Fuji Talc Ind. Co.,Ltd.) 0.8 parts by weight, silica (IMSIL A-8, manufactured by UNIMINCORPORATION) 0.8 parts by weight, and polyester pellet for coloringPESM6100 BLACK (manufactured by Dainichiseika Colour & Chemicals Mfg.Co., Ltd., 30% of carbon black content) 2 parts by weight. And in a samemanner as that in Comparative Example 1, a polyester fiber(multifilament) having a single fiber fineness of 50 dtex was obtained.

Comparative Example 3

To a polyethylene terephthalate (BELLPET EFG-85A, manufactured by NipponINIPET, Ltd.) dried by not more than 100 ppm of moisture contents 100parts by weight, added were tris(tribromo neopentyl)phosphate (CR-900,manufactured by DAIHACHI CHEMICAL INDUSTRY CO., LTD.) 10 parts byweight, and polyester pellet for coloring PESM6100 BLACK (manufacturedby Dainichiseika Colour & Chemicals Mfg. Co., Ltd., 30% of carbon blackcontent) 2 parts by weight. And in a same manner as that in ComparativeExample 1, a polyester fiber (multifilament) having a single fiberfineness of 48 dtex was obtained.

To a polyethylene terephthalate (BELLPET EFG-85A, manufactured by NipponINIPET, Ltd.) dried by not more than 100 ppm of moisture contents 100parts by weight, added were tris(tribromo neopentyl)phosphate (CR-900,manufactured by DAIHACHI CHEMICAL INDUSTRY CO., LTD.) 10 parts byweight, and polyester pellet for coloring PESM6100 BLACK (manufacturedby Dainichiseika Colour & Chemicals Mfg. Co., Ltd., 30% of carbon blackcontent) 2 parts by weight. And in a same manner as that in ComparativeExample 1, a polyester fiber (multifilament) having a single fiberfineness of 48 dtex was obtained. The obtained fibers were evaluated fortensile elongation and strength, flame resistance, gloss, transparency,devitrification resistance, cold setting property, curl holding power,and iron set property. Table 3 shows results.

INDUSTRIAL APPLICABILITY

According to the present invention, there may be obtained a polyesterfiber having outstanding flame resistance, curl-setting property,melt-dripproof property, transparency, devitrification resistance, andcontrolled gloss of fiber, while maintaining physical properties ofusual polyester fibers, such as heat-resistance and tensile elongationand strength, and may also be obtained artificial hair using thepolyester fiber.

1. A flame retardant polyester fiber for artificial hair made of acomposition obtained by melt kneading: 100 parts by weight of apolyester (A) comprising one or more kinds selected from polyalkyleneterephthalates and copolymerized polyesters having a polyalkyleneterephthalate as a principal component, and 2 to 20 parts by weight ofan organic cyclic phosphorus compound and/or a phosphoric ester amidocompound (B).
 2. The flame retardant polyester fiber for artificial hairaccording to claim 1, wherein the component (A) is at least one kind ofpolymer selected from a group consisting of polyethylene terephthalate,polypropylene terephthalate, and polybutylene terephthalate.
 3. Theflame retardant polyester fiber for artificial hair according to any oneof claims 1 and 2, wherein the component (B) is an organic cyclicphosphorus compound and/or a phosphoric ester amido compound representedby general formulas (1) to (9):

(where, R¹ represents a hydrogen atom, or a linear alkyl group, or analkyl group having a branch, and each of the R¹ may be identical ordifferent from each other, and R² represents a hydrogen atom, a linearalkyl group, or an alkyl group having a branch, a linear hydroxy alkylgroup, or a hydroxy alkyl group having a branch, a cycloalkyl group, asubstituted or non-substituted aryl group, or a substituted ornon-substituted aralkyl group);

(where, R¹ represents a hydrogen atom, a linear alkyl group, or an alkylgroup having a branch, and each of the R¹ may be identical or differentfrom each other, R³ represents a divalent linear alkylene group ordivalent alkylene group having branch, a linear hydroxy alkyl group, ora hydroxy alkyl group having a branch, a cycloalkylene group, analkylene group having ether oxygen in a principal chain thereof, asubstituted or non-substituted aryl group, a substituted ornon-substituted aralkyl group, an α,α′-xylylene group, asubstituted-α,α′-xylylene group, an α,α′-meta-xylylene group, or asubstituted-α,α′-xylylene group);

(where, R¹ represents a hydrogen atom, a linear alkyl group, or an alkylgroup having a branch, and each of the R¹ may be identical or differentfrom each other, R⁴ represents a hydrogen atom, a linear alkyl group, oran alkyl group having a branch, a cycloalkyl group, a substituted ornon-substituted aryl group, or a substituted or non-substituted aralkylgroup);

(where, R¹ represents a hydrogen atom, a linear alkyl group, or an alkylgroup having a branch, and each of the R¹ may be identical or differentfrom each other, and R⁵ represents a divalent linear alkylene group ordivalent alkylene group having branch, a cycloalkylene group, analkylene group having ether oxygen in a principal chain thereof, asubstituted or non-substituted aryl group, a substituted ornon-substituted aralkyl group, an α,α′-xylylene group, asubstituted-α,α′-xylylene group, an α,α′-meta-xylylene group, or asubstituted-α,α′-xylylene group);

(where, R¹ represents a hydrogen atom, a linear alkyl group, or an alkylgroup having a branch, and each of the R¹ may be identical or differentfrom each other, R⁶ represents a divalent linear alkylene group ordivalent alkylene group having branch, a cycloalkylene group, R⁷represents a hydrogen atom, a linear alkyl group, or an alkyl grouphaving a branch, each of the groups may be identical or different fromeach other, n represents 1 to 6);

(where, R¹ represents a hydrogen atom, a linear alkyl group, or an alkylgroup having a branch, and each of the R¹ may be identical or differentfrom each other, R⁸ and R⁹ represent a hydrogen atom, a linear alkylgroup, or an alkyl group having a branch, or a cycloalkyl group, Yrepresents a hydrogen atom, a linear alkyl group, or an alkyl grouphaving a branch, a cycloalkyl group, a substituted or non-substitutedaryl group, or a substituted or non-substituted aralkyl group, each ofthem may be identical or different from each other, and m represents 1to 3);

(where, R¹ represents a hydrogen atom, a linear alkyl group, or an alkylgroup having a branch, and each of the R¹ may be identical or differentfrom each other, R¹⁰ represents a divalent linear alkylene group ordivalent alkylene group having branch, a linear hydroxy alkyl group, ora hydroxy alkyl group having a branch, a cycloalkylene group, analkylene group having ether oxygen in a principal chain thereof, asubstituted or non-substituted aryl group, or a substituted ornon-substituted aralkyl group, X represents oxygen atom or sulfur atom,and 1 represents 0 or 1);

(where, R¹¹ represents a hydrogen atom, a linear alkyl group, or analkyl group having a branch, and each of the R¹¹ may be identical ordifferent from each other, R¹² and R¹³ represent a hydrogen atom, alinear alkyl group, or an alkyl group having a branch, a linear hydroxyalkyl group, or a hydroxy alkyl group having a branch, a cycloalkylgroup, a substituted or non-substituted aryl group, or a substituted ornon-substituted aralkyl group, and q represents 1 or 2);

(where, R¹¹ represents a hydrogen atom a linear alkyl group, or an alkylgroup having a branch, and each of the R¹¹ may be identical or differentfrom each other, R¹⁴ and R¹⁵ represent a divalent linear alkylene groupor divalent alkylene group having branch, a linear hydroxy alkyl group,or a hydroxy alkyl group having a branch, a cycloalkylene group, analkylene group having ether oxygen in a principal chain thereof, asubstituted or non-substituted aryl group, or a substituted ornon-substituted aralkyl group.)
 4. The flame retardant polyester fiberfor artificial hair according to any one of claims 1 and 2, whereinorganic fine particles (C) and/or inorganic fine particles (D) arefurther blended in a composition comprising component (A) and (B) toform fine projections on the surface of the fiber.
 5. The flameretardant polyester fiber for artificial hair according to claim 4,wherein the component (C) is at least one kind of material selected froma group consisting of polyarylates, polyamides, fluororesins, siliconeresines, cross-linked acrylic resins, and cross-linked polystyrenes. 6.The flame retardant polyester fiber for artificial hair according toclaim 4, wherein the component (D) is at least one kind of materialselected from a group consisting of calcium carbonate, silicon oxide,titanium oxide, aluminum oxide, zinc oxide, talc, kaolin,montmorillonite, bentonite, and mica.
 7. The flame retardant polyesterfiber for artificial hair according to any one of claims 1 and 2,wherein the flame retardant polyester fiber is of a form of non-crimpedfiber.
 8. The flame retardant polyester fiber for artificial hairaccording to any one of claims 1 and 2, wherein the flame retardantpolyester fiber is spun-dyed.
 9. The flame retardant polyester fiber forartificial hair according to any one of claims 1 and 2, wherein theflame retardant polyester fiber has a single fiber size of 5 to 100dtex.